Endpoint URL not found in axios PUT endpoint

When pressing a button, my app is suppose to subtract 1 from the current Quantity in the database where the name of the item is “CrossBag”

My PUT endpoint on the client:

confirm = () => {
    axios.put(`http://localhost:5000/merch/CrossBag`, {
        Quantity: this.state.merchInfo[0].Quantity - 1,
        });
};

The structure of my table merch where Name is the primary key:
enter image description here

The server side of the endpoint:

app.put('/merch', function (req, res) {

  connection.getConnection(function (err, connection) {

  if(err) 
  {
    console.log(err)
    return
  }

});
});

When I press the button though it states:

PUT http://localhost:5000/merch/CrossBag 404 (Not Found)

I’m a bit confused on how to update specifically that row’s Quantity. I read that you need some kind of ID to specify which row to change, so I made that ID my Primary Key (Name).

Can anyone provide me any guidance?